Radioreceiver



G. WALD RADIO RECEIVER April 10, 1934.

Original Filed March 4. 1931 #71 0775) 620/" f W Z W 29 a/WQPOST Patented Apr. '10, 1934 PATENT ()FFICE RADIORECEIVER George Wald, Mount Clemens, Mich.

Continuation of application Serial No. 519,960f

March 4, 1931. This application November 30,

1932, Serial No. 644,938

'7 Claims.

This invention relates to radio receivers. This application is a continuation of my application Serial No. 519,960, filed March 4, 1931. An object of this invention is to provide a radio I sound unit which is simple in construction, economical tomanufacture and which will reproduce audio signals with fidelity.

Other and specific objects will be apparent from the following detail description taken in connection with the accompanying drawing. in which Fig. 1 is a side elevation of the device.

Fig. 2 is a plan view.

Fig. 3 is a cross section on line 3-3, Fig. 2.

a A base 1 is preferably constructed of non-ferrous material and supports a unidirectional magnet 2. In the form shown in the drawing it is a permanent horseshoe magnet. Channel pole pieces 3. are secured'to each end of the magnet and form a continution thereof. A winding 4 is positioned in the channels of the pole pieces 3. leaving a space 5 for the accommodation of .an armature, and is adapted to be connected by wires 6 to an audio frequency circuit. The magnet 2 may be secured to and supported on the base 1 by a bar 7 and bolts 8, as clearly shown in the draw ing. As shown in the drawing the pole pieces 3 are attached to thebar of the magnet 2 by screws 9.

An armature 10 comprises a leaf or plate of magnetic permeable material suspended between the poles of the magnet in the space 5 and is, therefore, under the influence of the magnet 2 and the winding 4, or rather of the magnetism of the magnet 2 as modified by the flux produced in the winding 4 when the winding is connected to an'audio frequency circuit.

The bottom end of the armature 10 is free while the upper end is securedto one end of a cross arm 12 which is perpendicular to the plane of'the armature 10. A pedestal or post 13 is secured at its bottom to the base 1 and at its upper end-supports the cross arm 12. The pedestal 13 is perpendicular'tothe cross arm 12 and parallel with the armature 10.

A reproducing stylus 14 is secured to a tone arm 15, forming a continuation thereof, and is thereby connected to a reproducing diaphragm in a manner which is well understood in the art. In the drawing, Fig, 1, the reproducing stylus 14 and the tone arm 15 are illustrated as a part of a conventional reproducing apparatus of a phonograph.

It will be understood that the post 13 and the cross arm 12 are resilient. The'arrangement is ire-100.12)

such that variations of the magnetic flux will cause vibration of the armature 10, which vibrations will be transmitted to the reproducing stylus 14 resting upon the top of the pedestal 13. Actual experience has shown that when the armature 10 is supported in a manner as indicated and when contact is made with a reproducing stylus in the manner as shown and described, fidelity of reproduction is very much improved over that of other methods known in the art.

-Various changes may be made in the details of construction, within the scope of the appended claims, without departing from the spirit of this invention. The applicant does not intend to limit himself to the details of construction as specifically illustrated and described, which obviously may be varied, but defines his invention in the appended claims which distinctly point out that which is new.

I claim:

1. A radio receiving unit comprising a field structure adapted to be influenced by audio frequency current, an armature in the field of said structure, an arm normal to and supporting an end of the armature, the other end being free, a 30 resilient post normal to the arm and parallel to the plane of the armature, and a reproducing stylus adapted to rest upon the post substantially at the point of connection between the post and arm.

2. A radio receiving unit comprising a field structure adapted to be influenced by audio frequency current, an armature in the field of said structure, an arm normal to and supporting one end of the armature, the other end being free, 0 a resilient support normal to said arm and having one end secured to the arm and the other end being free. a resilient support normal to said arm and having one end secured to the arm and the other end rigidly supported. a reproducing dia- 05 phragm, and a tone arm therefor having its outer end in engagement with the support substantially at the point of connection between the arm and the support. I

3. A radio receiving unit comprising a field m0 structure including a unidirectional magnet and a winding adapted to be influenced by audio frequency current. an armature in the field, an arm normal to and supporting one end of the arma- 105 ture, the other end being free. a resilient support normal to said armancl having one end secured to the arm and the other end rigidly supported.

a reproducing diaphragm, and a tone arm theresupport substantially at the point of connection between the arm and the support.

4. A radio receiving unit comprising a field structure having a unidirectional magneltchanneled pole pieces and a winding positioned in the channels of the pole pieces and adapted to be influenced by audio, frequency current, an armature in the field of said structure, an arm normal to and supporting one end of the armature, the other end being free, a resilient support normal to said arm and having one end secured to the arm and the other end rigidly supported, and a reproducing stylus adapted to rest upon the support substantially at the point of connection between the post and arm.

5. A radio receiving unit comprising a field structure includinga unidirectional magnet and a winding adapted to be influenced by audio frequency current, a plate of magnetic material forming an armature and positioned in the field, an arm normal to and supporting one end of the armature, the other end being free, a resilient support normal to the arm and having one end secured to the arm and the other end rigidly supported, and a reproducing stylus adapted to rest upon said support substantially at the point of connection between the support and the arm.

its upper end, and a reproducing stylus adapted to rest upon the top of the post.

7. A radio receiving unit comprising a field base, a field structure including a unidirectional magnet having channelled pole pieces, a winding positioned in the channels of the pole pieces and adapted to be influenced by audio frequency current, a plate of magnetic material forming an armature and positioned in the field perpendicular to the base, a post perpendicular to the base and secured thereto at its lower end, an arm secured to the upper end'of the post and positioned normal to the armature and supporting the armature at the upper end thereof, the lower end of the armature being free, and a reproducing stylus adapted to rest upon the top of the .post.

GEORGE WALD. 

